In order to continuously shoot a subject, it is necessary to have a camera line of sight trained on an object. This task is often undertaken manually by the photographer, but it is difficult to perfectly track something like the bouncing of a ball that is high speed and has irregular movement. For this reason, research into systems for automatically controlling line of sight direction of a camera mechanically (so-called Active Vision: refer to non-patent publication 1 below) has become widespread in many fields.
With normal Active Vision technology, since the camera itself is moved while being attached to a drive platform, there is a delay in response speed with respect to movement in the line of sight direction. This makes tracking of a moving object that includes sudden acceleration changes (for example, a ball being used in a ball game) difficult. If the fact that the frame rate of a high speed camera reaches 1,000,000 fps in faster applications, and actual conditions where image processing is carried out at high speed by a GPU, are considered, it can be said that line of sight control speed is a bottleneck to the speed aspects in various tracking systems.
In order to solve this problem, an optical system known as a Saccade Mirror has been proposed, to carry out change of the line of sight of a camera at high speed using small drive mirrors arranged in front of a camera (refer to non-patent publication 2 below). With this technology, using two axis galvano mirrors makes high-speed line of sight change possible. Regarding a control system, if it were possible to control line of sight so as to always keep a physical object in the center of the screen, it can be considered that unprecedented dynamic shooting would become possible.
However, there is a problem in that pan angle and tilt angle are comparatively narrow with a conventional Saccade mirror.
As a device that can change line of sight in a wide angular range, the technology described in patent publication 1 below, for example, exists. With this technology, it is made possible to change line of sight direction in a wide range by changing mirror position using a so-called gimbal mechanism.